A phosphoimaging machine (Molecular Dynamics) will be purchased (with funds from the Cancer Center Support Grant CA07175 and departmental funds) as a core service facility for use by investigators at the McArdle Laboratory for Cancer Research. This machine will provide speed and accuracy in the quantitative imaging of radioactive blots. to use the machine, one must have a supply of phosphoimage screens. These screens and their accompanying cassettes represent a significant expense. To economize, the investigators participating in this grant proposal wish to purchase and use a common stock of these screens and cassettes. The purchase and administrative oversight of this common resource will constitute a core component of this program-project grant. This core component will be administered by a research specialist in Dr. Lamber's laboratory, who will maintain care of the screens and monitor their use by scientists in the five laboratories included in this grant proposal. Screens and cassettes will be stored in room 708, adjacent to Dr. Lambert's laboratory and proximal to all of the participating laboratories.